it is possible. see this tutorial here:
HDR Tutorial | High Dynamic Range Tutorial as he covers some of it.
I know his tutorial uses mostly photomatix and photoshop though, so you may want to google HDR tutorials specific to your programs.
To use a RAW image for HDR just open it up and make about 5 different exposures of the same image and save them separately. I usually go in stops of 1 when I do this (-2, -1, 0, +1, +2). Then you use them as if you had auto-bracketed when you initially took the photos. I have used this method with several of my images. I take the five exposure and my photomatix HDR and then blend them in photoshop until I am happy with the result. I like to err on the side of less rather than more with the HDR processing.
Hope this helps you some!